Today everybody knows about Diesel engines. They are everywhere—on streamlined trains, long-distance trucks, planes, ships, submarines. The fire-fated German dirigible Hindenburg was Diesel-powered; so was the big snow cruiser that Admiral Byrd shipped to Antarctica. But in the U. S. few know about the man whose name goes on the engines. Indeed, the word is often written lowercase. In the Encyclopaedia Britannica, Rudolf Diesel's biography gets just six lines.
In Germany last year appeared the first substantial biography of Rudolf Diesel, written by his son, Eugen. Last week in the U. S., Physicist Henry Crew of Northwestern University summarized it in the Scientific Monthly.
Rudolf Diesel was proud, sensitive, generous, an engineering genius, but not endowed with much money sense. He was a man of the world who spoke fluently not only German but French and English. His father, sprig of a Bavarian Protestant family which had produced craftsmen and tradesmen for generations, was a restless bookbinder who went from Augsburg to Paris. Rudolf, born in Paris in 1858, learned to use his hands in his father's atelier, delivered finished goods in a pushcart. Stirred by the ferment of new inventions—the storage battery, the gas engine, electric lights, dry-plate photography—the boy spent hours browsing in the Conservatoire des Arts et Métiers, two blocks from his home.
When the War of 1870 broke, all Germans were ordered out of Paris. The elder Diesel sought refuge in England, and sent the boy to an uncle in Augsburg. In trade school there, Rudolf set out grimly to be an engineer. When he was 20, studying at the Technische Hochschule of Munich, one of the lecturers, famed Professor Carl von Linde, mechanical-refrigeration pioneer, singled out young Diesel, sent him, after graduation, to work at the Linde factory in Paris. In a few months Diesel was acting as engineer, manager, inventor, patent expert, purchasing agent. He began to take out patents of his own—one for a means of making "clear ice," another for a gadget to make ice on the dinner table, in a carafe.
His refrigeration work impressed Diesel with the amount of heat generated when gases are compressed. This is the basic principle of the Diesel engine, which has no electric ignition. In a Diesel, air is sucked into the cylinder, then highly compressed by the piston motion so that its temperature rises to around 1,000° F. Atomized fuel is then shot into the cylinder where it is ignited by the heat. The high temperature enables the Diesel to burn cheap fuel. Powdered coal and cheap oil were the first fuels that Rudolf Diesel puttered with.
The inventor patented his engine blueprint in 1892 but the first experimental model was not completed until the next year. It was started by outside power, then fuel was injected. The engine blew up. Diesel was pleased. It had shown him that the heat of compression really was enough to ignite the fuel. Four more years of hard, steady work produced an engine with the highest thermal efficiency of any then in existence.